1. Field of the Invention
This invention generally relates to a bicycle rear derailleur. More specifically, the present invention relates to a stopper that limits pivotal movement of a base member of the bicycle rear derailleur relative to the bicycle frame.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. One component that has been extensively redesigned is the bicycle rear derailleur.
In many rear derailleur configurations, a base member of the rear derailleur includes a mounting axle that extends through the base member and into a portion of the bicycle frame. The mounting axle allows for limited pivotal movement of the base member relative to the bicycle frame. Further, such rear derailleurs often include a stopper member disposed between the base member and the bicycle frame that restricts the pivotal movement of the base member relative to the bicycle frame. Additionally the stopper member and/or bicycle frame can include an adjustment for setting an angular stop position of the base member relative to the bicycle frame. In some rear derailleur configurations, the adjustment for setting the angular stop position of the base member includes an adjuster bolt extending through a threaded aperture in the base member that contact the stopper member providing angular stop position adjustment.
With the stopper member disposed between the base member and the bicycle frame, the base member is spaced apart from the bicycle frame. In order to avoid rocking movement in a direction perpendicular to the pivotal movement of the base member about the mounting axle, the base member must be widened and the mounting axle must be elongated. The additional length of the mounting axle and widened base member are not desirable in current rear derailleur designs where mass and space are important design considerations.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved rear derailleur that includes a stopper member configuration that does not require a widened base member and elongated mounting axle. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.